busybox/util-linux/dmesg.c

81 lines
2.0 KiB
C

/* vi: set sw=4 ts=4: */
/* dmesg.c -- Print out the contents of the kernel ring buffer
* Created: Sat Oct 9 16:19:47 1993
* Revised: Thu Oct 28 21:52:17 1993 by faith@cs.unc.edu
* Copyright 1993 Theodore Ts'o (tytso@athena.mit.edu)
* This program comes with ABSOLUTELY NO WARRANTY.
* Modifications by Rick Sladkey (jrs@world.std.com)
* Larger buffersize 3 June 1998 by Nicolai Langfeldt, based on a patch
* by Peeter Joot. This was also suggested by John Hudson.
* 1999-02-22 Arkadiusz Mi¶kiewicz <misiek@misiek.eu.org>
* - added Native Language Support
*
* from util-linux -- adapted for busybox by
* Erik Andersen <andersen@codepoet.org>. I ripped out Native Language
* Support, replaced getopt, added some gotos for redundant stuff.
*
* Audited and cleaned up on 7 March 2003 to reduce size of
* check error handling by Erik Andersen <andersen@codepoet.org>
*/
#include <stdio.h>
#include <stdlib.h>
#include <errno.h>
#include <sys/klog.h>
#include "busybox.h"
int dmesg_main(int argc, char **argv)
{
char *buf, *tmp;
int bufsize = 8196;
int i, n = 0;
int c = 3;
i = bb_getopt_ulflags(argc, argv, "cn:s:", &buf, &tmp);
if (i & 1)
c = 4;
if (i & 2) {
c = 8;
n = bb_xgetlarg(buf, 10, 0, 10);
}
if (i & 4)
/* I think a 512k max kernel ring buffer is big enough for
* anybody, as the default is 16k... Could be wrong though.
* If so I'm sure I'll hear about it by the enraged masses*/
bufsize = bb_xgetlarg(tmp, 10, 4096, 512*1024);
if (c == 8) {
if (klogctl(c, NULL, n) < 0)
goto die_the_death;
goto all_done;
}
buf = xmalloc(bufsize);
if ((n = klogctl(c, buf, bufsize)) < 0)
goto die_the_death;
c = '\n';
for (i = 0; i < n; i++) {
if (c == '\n' && buf[i] == '<') {
i++;
while (buf[i] >= '0' && buf[i] <= '9')
i++;
if (buf[i] == '>')
i++;
}
c = buf[i];
putchar(c);
}
if (c != '\n')
putchar('\n');
all_done:
if (ENABLE_FEATURE_CLEAN_UP) {
free(buf);
}
return EXIT_SUCCESS;
die_the_death:
bb_perror_nomsg_and_die();
}